As a bobbin for winding an optical fiber strand or a coated optical fiber (in the present specification, these will be collectively referred to as an optical fiber), for example, a bobbin, whose main winding flanges are provided with both ends of a cylindrical main winding body portion as disclosed in Patent Document 1, is used. In addition, when shipping an optical fiber, the optical fiber is generally shipped in the form of a product obtained by winding the optical fiber on a bobbin, that is, in the form of a bobbin-wound optical fiber.